Use 3 faulting mechanism classes using classification of Zoback (1992):

Normal

ENF= 1 and ETF= 0. 11.8% of records.

Reverse

ETF= 1 and ENF= 0. 47.8% of records.

Unspecified

ENF= ETF= 0. All have Mw< 5.0. 35.9% of records.

Discard the 4.5% of strike-slip records as not representative of area.

Use 4 locations w.r.t. Po Plain and eastern Alps (PEA) and distance (corresponds to index j of c1 and
c2):

1.

Sites within PEA and R ≤ Rh.

2.

Sites within PEA and R < Rh.

3.

Sites within northern Apennines (NA) and R ≤ Rh.

4.

Sites within NA and R < Rh.

Rh= 70km. Use relation LATref= -0.33LONs+ 48.3, where LONs is station longitude and LATref
is reference latitude. Positive differences between station latitude and LATref imply PEA and negative
differences imply NA.

Data from 44.0–46.3∘N and 8.0–13.5∘E. Most (60% of records) data from 20/5/2012 (Mw6.1) and
29/5/2012 (Mw6.0) Emilia earthquakes and aftershocks plus the Friuli 1976–1977 sequence. Data from
permanent and temporary stations of national Italy network (Rete Accelerometrica Nazionale), INGV
network plus 3% from other Italian, French and Swiss networks. Data extracted from ITACA 2.0 database.

Plot PGAs v rjb for 29/5/2012 Emilia earthquake and find that PGAs at stations to north of Po Plain
are 3–5 times larger than that to the south for rjb> 50km, which relate to reflections off the Moho (SmS
phase).

Do not include magnitude saturation in functional form because no evidence from data.

Compare predictions and observations for data around Mw6 and Mw4.5 and find good match.